THE ORIGIN OF COTTON

Cotton is a vegetable seed fibre, which is attached to the several species of the
genus Gossypium, which belong to the natural order of Malvaceae. The cotton plant is a
shrub, which reaches the height of 4 to 6 feet. The perennial tree cottons are also found
in some areas. The development of cotton textile appears to have taken place in the
Indus valley of Pakistan. (The earliest known cotton fabrics in the old world belongs to
the Indus civilization, indicating that the development of cotton as a major raw material
took place in Sindh). These fabrics were found during excavations at Mohenjo-Daro in
Sindh at levels, which are dated at approximately 3000 BC. In the new world the cotton
seed and primitive cotton fabrics were found in the excavation at Northern Peru, dated
about 2500 BC.
In the 18th century the imports of woven cotton goods from India created such a
demand in Europe that much of the spinning and weaving industry traditionally based
in wool and flax was diverted to the production of cotton goods. The invention of
spinning machine by James Hargreaves in which the modifications were brought by
Richard Arkwright in 1768 (who also established first ever spinning mills in 1775 in
which the water power was used) and the invention of power loom by Edmund
Cartwright, so increased the efficiency of the industry as to create a huge potential
demand for raw cotton. The newly founded United States of America, in particular,
were willing and able to extend the planting of cotton to meet this demand, and the
invention of the saw gin by Eli-Whitney in 1793 removed a major constraint on cotton
production.
Although cotton has been grown in Egypt since about the 14 th century, it does not
appear to have been an important crop & Egypt was importing cotton from Syria and
Cyprus in till 16th century. The crop only assumed importance when cotton from USA
replaced the old world cotton about 1820. later on the successful attempts were made to
grow long staple Sea Island cotton. New varieties of American origin were developed in
Egypt and how Egyptian cotton is famous for its extra long staple.
 In India the expansion of cotton growing in the 19th and early 20th centuries was
almost entirely in short staple desi-cottons. In the early 1900’s the Indo-American
cottons of G.hirsutum were developed to the stage that they have now replaced almost
completely the indigenous cottons in Indo-Pak. Sub continents.

GEOGRAPHICAL DISTRIBUTION
Cotton is generally regarded as a tropical crop, but at present about two third of
the world production comes from north of latitude 300N where the major produces
USA, China and former Russian states are located. About 10 % of the total crop comes
from the southern hemisphere while 25% from the northern tropics up to 30 0N. this
range of conditions helps to spread supply of cotton throughout the year.
COTTON SPECIES
The cultivated cottons are found in four of the species of Gossypium
Gossypium arboreum: origin in Indian sub-continent.
Gossypium herbaceum: origin is not clear, but this species is associated with the
expansion of Arab influence
Gossypium barbadence: Peru in south America
Gossypium hirsutum: West Indies, south Mexico and Central America.

Gossypium hirsutum is undoubtedly the major specie grown on at least 70% of the
total area and 85% of the total production. Gossypium arboreum is grown in China,
India and Pakistan, Thailand. Gossypium herbaceum is grown only in India and Iran on
11% and 15% of the total area respectively. Gossypium barbdence is grown in a number
of countries but not more than 5% of the total area.
Asiatic cotton belong to G.arboreum and G.herbeceum once played a major role
in the cotton industry but now they are disappearing because of their low yield and
short fibres. A small quantity of very coarse fibre from G.arboreum is exported for
special needs such as mixing with wool etc.
 The Egyptian and Sea land cottons are derived from the botanical species G.
barbedense. Such cottons are most valuable, the difficult to produce and are the least
abundant. The varieties of Egyptian cotton gained ascendance in supplying the demand
for fiber counts. The pima cotton is now raised in the south-western United States and
Northern Peru.
In 1910 the United States Department of Agriculture (USDA) published a
bulletin listing more than 600 varieties of Upland cotton. In recent years however this
number has been noticeably decreased and now only 7 varieties produce 70% of the
cotton crop. The average life of a successful cotton variety is usually 10~15 years. A
new variety is usually has very similar or slightly improved fibre characteristics to those
of the one it replaces, so as not to upset established markets for the lint, but shows
significant improvements in other ways such as yield, ginning percentage (G.O.T),
disease and pest resistant or vegetative characters.

COTTON VERSUS MAN MADE FIBRE

In the industrial world the main competitor of cotton is the wide range of man-
made fibres, while the wool production has grown comparatively slowly, the production
of silk and linen are statistically unimportant. The increase in the market share of man-
made fibre, particularly synthetics is a challenge to the competitiveness of cotton.
The total mill consumption of all textile fibres in the world in 1958 was 13.5
million metric tons & it increased upto & above 50mmt in 1999 consumption rate
became more than four in these 40 year, mainly due to the increase in the world
population.
In case of cotton the total mill consumption has increased from 9.5 MMT from
1958 to 1998, giving a annual growth rate of more than two percent wool consumption
only increased slightly from 12.7 to 15.90 thousand metric tons, where as regenerate
fibre consumption increased slightly from 22.74 to 30.78 thousand metric tones. The
most spectacular growth is observed for synthetic fibre specially after 1960. from 1960
to 1970 the consumption of these fibres increased from about 0.7 MMT to 4.7MMT and
&in 1999 it is 26.5MMT.
The relative share of different fibres in total world consumption indicates that
while the consumption of cotton in absolute terms has been increasing at a steady rate
of about 2% per year but its relative share in percentage had been steadily decreasing
from a value of approximately 70.7% in 1958 to roughly 47% in 1999. where as
synthetics have increased their share from only 3% in 1958 and more than 50% in 1999.
The first man-made fibre i.e regenerated cellulose fibre was introduced in 1930
as a substitute for silk and was known as artificial silk. Later on its was used as a
synthetic for cotton. In about 1950 the synthetic fibres made their first appearance
textile world significantly influence the consumption of all textile fibres. The
impressive gain in the production of synthetic fibre was achieved by the developing
countries like China, Korea, India, Taiwan, Indonesia, Pakistan etc, with in MMF the
shore of synthetic is nearly 80% and polyester retains the pride of place among
synthetic fibres.

The demand for textile varies from year to year, and changing fashions and
consumer preference influence the demand for different types of fibre. But the supply of
MMF cannot be adapted quickly to changing circumstances. It require capital
investment and industrial plant and it may be several years before the necessary finance
and construction are completed and the production can start. The cotton grower on the
other hand can substantially decrease or increase the cotton area with in a year by
switching to or from alternative annual corps. Both large scale and small growers react
quickly to changes in price. In the long term shortage of suitable land may limit the
production of cotton but there is no such limitation on the production of MMF.
A major disadvantage of cotton compared with MMF is the amount of waste in
the manufacturing process. This consists mainly of trash, dirt and short fibres. The
removal of trash and dirt is not only a direct loss, but involve additional processes and
has a significant effect on lint quality. All cottons contains a proportion of short fibre
but cleaning machinery, badly set gins etc increase this proportion by breakage of the
longer fibre. Other complaint about cotton relate to stickiness caused by white fly and
aphids in the field.
The increase in world demand for textile fibres is expected to continue not only
due to increase in world population, but also due to the increase in the standard of living
in the less developed countries. In the developed countries consumption has stabilized
around 10 Kg. To maintain its share in this increase, cotton promotion must be
intensified in the developed & developing countries. Many of the developing countries
are themselves cotton produces and any increase in consumption is likely to favour
cotton.

COTTON SITUATION IN PAKISTAN

Pakistan is basically an agricultural country and holds a prominent position in

the cotton map of the world. Cotton is the main cash crop which contributes
substantially to the national income. Raw cotton and cotton based products are the main
export items of the country.
The textile industry in Pakistan having a short span of life is a backbone of the
country’s industrial economy. It provides roughly 38 % of industrial employment and
contributes 62% to Pakistan export earnings.
At the time of independence the total production of cotton was only 1.1 million
bales and local consumption was 75000 bales. With the expansion of textile industry
particularly after 1951 the cotton consumption rate started increasing. The rise in export
during the 60’s was mainly due to the successful efforts on the part of Pakistan
government through its first and second five year plan for increasing cotton production
upto a level of more than 25lac bales. During the years 1971 to 1973 cotton production
showed a new record and about 33 lac bales per year were produced mainly due to
favorable season and high yielding varieties. However this production fell down to 19
lac bales in 1976~77 due to political disturbances and adverse government policies.
The average world yield per acre in 1949~50 was 222 lbs that of Pakistan 176
lbs /acre and jumped up to 480lbs/acre for the world and 500 lbs/acre for Pakistan,
exceeding the world average.
The production of cotton crop has suffered consecutively for the last many years
after achieving the record production of 10.5 million bales during the year 1991~92 and
down to only 8 million bales in 1992~93. however due to favorable season and
evolution of C.L.C.V resistant varieties the production of cotton was about 11 million
bales & yield of 572 lbs/acre during the year 1999~00.
The yield can easily be doubled if the high yielding G.O.T varieties are evolved,
suitable growing area is selected, suitable agronomic and plant protection measures are
adopted. As a matter of fact there are many progressive farmers in Punjab and Sind are
already harvesting more than 1000 lbs/acre. Breeders, agronomist and researchers can
easily guide the grower to achieve this objective during the 21st century.
1 bale of raw cotton = 375 lbs (Pakistan)
1 bale of raw cotton = 480lbs (international)

THE COTTON PLANT

Cotton requires 5 to 7 months of warm or hot weather, plenty of sunshine and

appreciable amounts of moisture for optimum development. When the cotton seed
germinates the first sign of activity is the emergence of the radical fro the pointed end
of the seed. This turn do-onwards anchoring the seedling in the soil and resists any
downward movement when the hypocotyls develops about two days later. The
hypocotyls is bent backward as it pulls the cotyledons clear of the ground, and then
quickly straightens bringing the stem and cotyledons into an upright position.
If the soil is too hard or is capped with a hard layer above the seed, the
hypocotyls may not be strong enough to pull the cotyledons free, and is in loose soil the
seed coat will be pulled out of soil and drop off. The seed should be sown at a depth of
2~4 cm and deeper in dry conditions.
The cotyledons are an opposite pair of simple leaves with short stalls. They open
about 5 cm above ground level but this depends upon the moisture supply and the depth
of sowing. The leaf arising from the node immediately above cotyledons is called first,
true or rough leaf.
The flower bud first becomes visible as a small green cone. The dry before
flowering the conical bud starts to enlarge rapidly. The date of first flower is an
indication of the earliness of the crop depends upon a number of factors like
temperature water supply verity etc. when the blossom have fallen, a small dark green
triangular pod forms. Mean time the seeds and fibres have been formed inside this boll.
At complete maturity the fibre expansion causes the boll the bursts and opens in to
section.
The time between planting of seed and flowering of plant ranges from 80~110
days and between flowering and opening of the boll 55~80 days. The long & fine
varieties take long time to mature. The mature fibre is picked as soon as possible after
the opens to minimize deterioration of fibre by light & moisture.

Cotton Fibre Quality

The role that quality plays in the marketing of cotton is unique among all other
field and fruit crops. Cotton quality alone is expressible by a multitude of measurement.
In the other field crops, quality is expressed by 1 or 2 measurements. Cotton quality has
historically employed both visual and mechanical methods to determine quality.
Recently cotton classing has been converted to high volume instrument i.e HVI System
where quality is almost entirely determined by instrument. The use of HVI to assess
quality allows the development of a marketing system that encourages producers and
ginners to enhance and preserve quality.
Fibre Fineness
A relative measure of size, diameter,linear density and/or mass per unit length of
fibres.
Fineness is one of the three most important fibre characteristics. The fineness
determines how many fibres are present in the cross-section of a yarn of given
thickness. Additional fibres in the cross-section, provides not only additional strength
but also a better distribution in the yarn.
The cotton fibre cannot be specified by reference to diameter because the section
is seldom circular and is thus not easily measurable.
Cotton fibre fineness is usually specified by the relation of mass (weight) to
length. i.e linear density such as
Micron gram/inch
Tex = mass (g) /length (km)
Denier = mass (g) /9000 m
To define cotton fineness both perimeter (or total surface area) and cellular
thickness (or total volume of cellulose) must be known. Surface area can be expressed
as area per unit volume and can be estimated directly with an air flow instrument. From
the basic theory of fluid flow, it can be shown that the air permeability of a teat
specimen of a specified mass in a chamber of specified dimensions in its surface area.
The micronaire tester is the most widely used instrument to measure surface area of
fibre. The micronair scale was originally calibrated by using the measured linear
density(fineness) of test cotton. The instrument readings were assumed to indicate
gravimetric fineness in micro grams per inch. Experience on broader ranges of samples
showed that the scale did not represent gravimetric fineness. Fibre surface area is the
property measured by the instrument. Although micronaire is not literally “fineness”, it
is recognized by many to be a very important measurement for determining the value of
cotton and criteria for selection in yarn spinning.
 Cotton is a natural fibre, it grows in various soils, in various climates and with
annually changing cultivation conditions. The fibre therefore cannot be homogeneous in
their characteristics including fineness.
FINENESS SCALE
Micronarie Fineness
Value
>6 Coarse
5~ Slightly Coarse
Medium
Fine
Very Fine(immature for G.hirsutum)

Maturity
Microanire differences are governed by changes in perimeter or in cell wall
thichness or by changes in both. With a variety, cotton fibre perimeter is fairly constant
and maturity will cause a change in micronaire. Consequently micronaire has a high
correlation with maturity.
Maturity is the degree of development of cell wall thickness.
Fine cotton varieties with small perimeter (surface area) have low mike,
even when mature because they have small diameter fibres and small surface areas. As
fibre perimeter decreases, the ratio of surface to weight increases, placing more surface
area in the test specimen of specified weight.
Some methods of maturity measurement
 Direct microscopic examination and classification of alkali swollen fibres.
 Dyeing method
 Double compression air flow measurement
 Causticaire method
 Near infra red spectroscopy
 X- ray fluorescence spectroscopy

Maturity = Degree of cell wall development

FIBRE LENGTH

The 50% span length is the distance spanned by 50% of the fibres extend from a
clamp in which they have been caught at random along their length.
The 2.5% span length is the distance that 2.5% of the fibres extend from a
clamp in which they have been at random along their lengths.
Upper half mean length : The average length of the longer half of the fibres. It
is obtained by drawing a tangent from the 50% point on the Y-axis to the curve and
extrapolating to the X-axis

Short staple < 25mm

Medium 26~29mm
Long 30~35mm
Extra long > 35mm
Staple Diagram
The fibres in the boll do not exhibit extremely great length differences.
Noticeable shorting of many fibres arises before the spinning process owing to ginning
and cleaning. In even the smallest tuft of cotton taken up in the hand, there will be all
lengths from the absolute minimum (2mm) to the absolute maximum (more than
30mm). If the fibres of such tuft are arranged next to each other with their ends aligned
and sorted according to length then the staple diagram (numericl or Hanteur) will be
obtained.
If the diagram is derived abstractly from the masses of length groups then
the weight biased diagram is obtained. This has notably higher curve compared with
numerical diagram because long fibres has more mass than short fibres.
Fibrogram
In addition to the staple diagram, the fibrogram is available. Where as in
the staple diagram the fibres are aligned in one end, & in the fibrogram they are
arranged randomly by clamping on a line. It give good representation of the drafting
operation and of the arrangement of fibres in the yarn. It is produced by digital
fibrograph or HVI. The length are stated as span length i.e length, which span a certain
distance
From these length uniformity is calculated
Uniformity Ratio % = (50% SL/2.5% SL)*100
Uniformity Index % = (ML/UHML)*100

Uniform Above 80%

Average 75~80 %
Irregular Less than 75%
(UR % range in 40~50 %)]
A high uniformity indicates that the mean length is close to the UHML. Under
these conditions, few short fibres (<1/2 inch) are present, thereby reducing waste in the
spinning mill.

COTTON FIBRE STRENGTH

The fact that strong yarn cannot be made from weak fibres, confirms that
strength is a very important criteria for evaluating cotton for utilization in spinning.
There are two general methods of determining fibre strength. The single fibre method
and the fibre bundle method.
Considering that there are millions of fibres in a very representative of the
millions of fibres involved in the spinning process. Because all fibres do not have the
identical strength and because fibres in yarn are in a bundle arrangement, the fibre
bundle method provides representative test data (not only because of the increase in the
number of fibres being tested but also because strength of yarn is dictated by fibres in
an arrangement to that of fibres in the bundle method of determining strength).
In bundle method strength is determined by clamping a bundle of fibres
between a pair of jaws (clamps) and increasing the swparation force intil the bundle
breaks (eg pressley strength tester, stelometer, HVI)
 In the pressley instrument the clamps are usually set at “zero guage” i.e
the clamps are touching each other at the start of the test and the results are reported in
thousand pounds per square inch. In the stelometer and HVI there is a gap of one eight
of an inch between the clamps (1/8 gauge) and results are reported in grains per tex.
Both instruments can, however be set for “0”,1/8 inch gauge.
The results of 1/8 inch gauge tests are more closely correlated to the
results of spinning tests (yarn strength) than are those of zero gauge. Moreover,
regardless of genetic variety there is a weak place within every 1/8 inch (3.2cm)
distance along cotton fibres. When there is no space between clamps (zero gauge), the
probability that the fibres will break at a weak place is extremely low, true strength will
not be revealed, the test will almost always indicate a strength higher than the actual
strength. But when there is a 1/8 inch space between clamps cotton will always break at
weak places revealing the true strength of the fibres.
Moisture content plays a important part in fibre strength. The strength of
cotton increase as its moisture regain + increases. The experiments showed that when
moisture in cotton was increased from 6.5%~9.5% the strength increased from 25.6
g/tex to 32.0 g/tex. It is therefore important to condition the sample at the standard
temp, and humidity levels until equilibrium is achieved.

STRENGTH RATING
Pressely (0 gauge) 1/8 g/tex
TPPST
Very strong 98 & above 30 & above
Strong 91~97 27~29
Average 86~90 24~26
Fair 80~85 21~23
Weak 72~79 20.2 & below

IMPURITIES IN COTTON (TRASH)

 In addition to useable fibres, cotton stock contains foreign matter of
various kinds.
Vegetable matter
Husk portion , seed fragment, stem fragments leaf
fragments, wood fragments.
Mineral material
Earth, sand, dust etc.
Other foreign matter
Metal fragments, cloth fragments, packing material(jute,
polymers), sugar, stickiness

Fibre fragments
Which finally make up the greater portion of dust. This
foreign matter can lead to extreme disturbance during processing.
Dust consists of small and microscopic particles of various substances
CLASSIFICATION
Trash Above 500m
Dust 50~500m
Micro dust 15~50m
Breathable dust Below 15
(the particles between 5m carries endotoxins that cause lungs diseases).
Trash /foreign matter
Upto 1.2% Very clean
1.2~2% Clean
2~4 % Medium
4~7% Trashy(dirty)
7% & above Very trashy

A popular trash measuring device is the Shirley Analyzer which separates

trash and foreign matter from lint by mechanical mean. The result is expression of trash
as a percentage of the combined weight of trash &lint of a sample. Video scanning
trashmeter are used in HVI. These trash meters employ a television camera to identify
on the surface of cotton sample, region or areas darker than a predetermined reflectance
as trash. It analyzes two parameters; count (no of pieces of trash seen by the video) and
percent area (the ------- of the areas all pieces of trash in relationship to the area of the
viewing window)

COLOUR GRADES OF COTTON

Colour has been one of the primary factors of cotton quality (from the
very beginning of commercial trading throughout the years colour has been) primarily a
matter of visual judgment by cotton classers. While the eye is exceptionally sensitive to
small differences in colour, it is not as good a judge of absolute colour levels.
The effect of cotton colour on processing and on manufactured products
has primary importance. Colour is particularly important as a measure of how well yarn
of fabric will dye or bleach.
In 1927 Dorothy Nickerson of the USDA, cotton division was assigned
the job of developing way and means of putting cotton standards on a scientific basis
through the use of instrument measurement. The outcome of this work was the
Nickerson-Hunter Cotton Colorimeter built by spinlab ltd in 1959. The distinguishing
feature of this instrument is the grade diagram.
Colour is associated with light waves, specifically their wavelength
distribution. Visible wavelengths are these between the violet and red ends of the
spectrum. Wavelength not absorbed are those reflected by objects and thus visible to
observer.
There are three attributes of colour, hue, saturation and lightness. They are
related to each other as shown
Cotton contains no blueness or greenness and very little redness.
Therefore it is in a relatively small and narrow range of whiteness and yellowness thus
it may be examined in two dimensions rather than three
COLOUR CHART
Rd (reflectance) & +b (yellowness) are physical measured parameters
JS Grade is composed of colour, leaf, preparation
7 grades of white code 11/21/31/41/51/61/71
5 grades of spotted code 23/33/43/53/63
3 grades of tinged code 34/44/54
43 grades are defined by USDA

USDA UPLAND COTTON GRADES

White
GM 11
SM 21
MID 31
SLM 41
LM 51
SGO 61
GO 71
Lighted spotted
GM (lt-sp) 12
SM (lt-sp) 22
MID (lt-sp) 32
SLM (lt-sp) 42
LM (lt-sp) 52
SGO (lt-sp) 62
Spotted
GM (sp) 13
SM (sp) 23
MID (sp) 33
SLM (sp) 43
LM (sp) 53
SGO (sp) 63
Tinged
SM (tg) 24
MID (tg) 34
SLM (tg) 54
LM (tg) 64
Yellow stained
 SM(ys) 25
MID(ys) 35
Light gray
GM (lt.gray) 16
SM (lt.gray) 26
MID (lt.gray) 36
SLM (lt.gray) 46
Gray
GM (gray) 17
SM (gray) 27
MID (gray) 37
SLM (gray) 47
Below grads
BG 81~87
 CHEMICAL COMPOSITION OF COTTON AND ITS EFFECT
UPON FIBRE PHYSICAL PROPERTIES
The chemical composition of the material is the determining factor in its
behaviour toward any chemical treatment. The composition of the cotton fibre reflects it
cellular nature. Although cellulose is the major constituent, any of the substances
commonly found in plant cells may be expected to be present in at least small amounts.
The typical mature cotton has a composition given in the following table.

COMPOSTION OF A MATURE COTTON FIBRE (dry basis)

Constituent Min Max Avg. %

% %
Cellulose 88 96 94
Protein 1.1 1.9 1.3
Pectic substances 0.7 1.2 0.9
Ash 0.7 1.6 1.2
Wax 0.3 1.0 0.6
Organic acids 0.5 1.0 0.8
Other - - 0.9

Cellulose
The cellulose content of raw cotton fibre ranges from 88~96 % of
the dry weight scoured, bleached dry cotton fabric is approximately 99 % cellulose. The
variation in the values for the cellulose contents of raw cotton fibre is due mainly to
natural variation brought about by conditions of soil, climate and variety of cotton and
especially to conditions which arrest fibre development such as drought, disease and
early frost. Low cellulose content usually indicates considerable numbers of thin
walled, immature fibres which contain a high proportion of non-cellulose substances.

Wax
 The material extracted from cotton fibre with the help of benzene, either
or other organic solvents is usually referred to as wax. From the stand point of
processing, wax is the most important group of constituents of the fibre other than
cellulose (the typical mature cotton fibre contains about 0.6% wax and most of the
values reported range between 0.4 and 1.0%)
Most of the wax is located in the primary wall of the fibre. The wax has a
profound influence on the wetting properties of the fibre. Raw cotton will float for days
on a water surface, while dewaxed cotton (by heating with dilute sodium hydroxide or
by extraction with organic solvent) will sink in a few minutes. The presence of wax is
necessary for proper spinning since it lubricates the fibre. Owing to its lubricating
properties, however the higher wax contents of cotton decreases the tendency of the
fibres to cling to each other, reduces the friction between fibres and hence lowers the
tensile strength of yarn and fabrics. Increase of as much as 25% in tensile strength have
been reported when yarn or cord made of raw cotton was extracted with benzene or
other wax solvents.
(Melting point of wax 72~780C)

PECTIN AND RELATED SUBSTANCES

Pectin or materials closely related to them are after found with cellulose. (the
typical mature cotton fibre contains from 0.6 ~1.2% pectin. The amount reported also
depends on the method of determination)
It has been suggested that pectin in the substance cementing the cellulose
together, but this idea has not received acceptance or experimental verification. Tensile
strength is not greatly attend by removal of pectin.

PROTEIN
The protein occurs in the lumen and in the primary wall. The nitrogen is
readily removed from the cotton by a mild alkali boil. As a means of controlling the
scouring and bleaching operations analytically, the estimation of nitrogen is therefore of
little value. Little is known about the composition and properties of the protein of the
cotton fibre.
The protein of the cotton fibre appears to have only a minor effect on the
dyeing properties. High nitrogen content of finished fabrics resulting from poor
scouring is said to favour damage by bacteria.

ASH AND ITS CONSTITUENTS

A typical sample of raw cotton will contain about 1.2% of ash of
approximately the following composition.
K2O = 34% , CaO = 11% , MgO = 6% , Na2O = 7% , Fe2O3 = 2% ,
Al2O = 2% , SiO2 = 5% , P2O5 = 5% , Cl = 4% , CO2 = 20% and traces of Cu, Mn,
B, Zn. (verification considerably above and below these value are recorded. These large
variations appears to be due to analysis of cotton containing sand, soil and dust, and to
faulty methods). The variations in ash constituents arising from differences in soil,
climate and kind of cotton is strongly alkaline. About 85% of the ash may be removed
from the fibre after extraction with water but most of the Ca, Fe and Aluminium remain
in fibre. The ash contents of cotton with water greatly increases its electrical resistance
(by removing most of the soluble potassium and sodium salts), made possible its
adoption as substitute for silk as electrical insulation on telephone cords, wire and
cable. The mineral content of cotton fabric may affect dyeing properties.
FACTORS AFFECTING YIELD & QUALITY OF COTTON:
1. Soil type
2. Climate
3. Time of sowing
4. Land management & preparation
5. Variety of cotton
6. Quality of seed
7. Plant population
8. Crop rotation
9. Irrigation
10. Plant pests
11. Plant diseases
12. Plant protection measure
13. Cotton control acts
14. Cotton ginning
15. Marketing price
16. Grade of cotton
17. Govt policies
18. Fertilizer
19. Cotton picking
20. Mechanical harvesting

1. Soil type:
For better yield the soil should be well drained homogeneous, medium textured,
rich in organic matter, for easy penetration of air, water, roots and balanced supply of
nutrients.
Soil varies from place to place under different conditions. Some soils are;
a) Sandy divides any organic matter, unable to support growth and development of
cotton crop.
b) Absolutely Hard Clay:
Do not permit water to move down & hardly germination of cotton seed occurs
under such conditions. The major characteristics are that they do not retain soil water
and can not help in the growth of plant. Although germination will take place but
further progress will cease. Other types are sandy loam & Clay loam.
Sandy soils are found in great Thul of Punjab Mianwali, Mazzafargar,
Bahawalpur division, and part of Rehim Yar Khan adjoining Rajuputana from Rajustan
of India & Sind desert area which is closer to Rajustan. As general rule cotton growing
in such type of land is possible if irrigation facilities are available.
Cotton can be grown by increasing the organic matter of the soil through the
addition of salt, farmyard manure & green measuring of crops like gowara, jenter,
Berseem and other leguminous crop. The results have shown that under such
conditions extremely rarely sowing of cotton i.e. in the moth of March and early April
is very much suited for the germination of seed and plant will be enough grown up
before the start of high temp. Sand storm from April to august are unable to change the
well grown seedling. Additional factors under such desert condition for successful
cotton growing are planting of hedges of junter around the cotton field and between the
cotton field at the time of cotton sowing.
Hard clay soils:
Such soils are found in upper Thul I.e. Khoshab ,Shahiwal & in most of the area
of in D.G Khan Division in Punjab and Nisarabad Subdini of Bluchistan. Similar soils
are fund also in Dara Ismail Khan and west bank of the rever Indus in Sind nd in
N.W.F.P. In this case water permeability is very poor. Soil plaughing is difficult and
sowing of cotton is not so simple. In extreme cases % age of salt is also very high ad
under such conditions. Germination of seed is difficult and yaing seedling fret difficulty
in growth and development for such soils addition of F.Y. manure composed of organic
matter and green mauring is helpful in loosening the soil texture for the penetration of
water, germination of seed, seed growth, and plant development .
In the rest of the Punjab, Sind, N.W.F.P and Baluchistan soils are loamy, Sandy
loam or clay loam. Both these types are suitable for the successful cultivation of cotton
crop, hence the basic factor for the successful cotton crop cultivation is the soil type. In
the early years of colonization of new land yield of cotton is very low and gradually
with the improvement of cropping conditions. Cotton yield also improve.

2) Climate;
Cotton plant is extremely sensitive and delicate yet being grown since prehistoric
time in different parts of the world. It is an established fact that Indus valley was the
original home of cotton, excavation from Herpa and Monhungodaro shows that cotton
was even exported to other countries in three thousand years B.C. It has been later on
found that the short staple G. Herbassium cotton was originally grown in western
countries and north Africa from where it spread are over the world. However, it is
grown b/w 60º north and 60º south of the equator in both the hemisphere. In Pakistan
the cotton growing treats are Multan, Bahawal pur, Bahawal Nigar, faisalabad,
Sargodha, Hyderabad, Nawabshah division and parts of the Lahore, Gjranwala,
Rawlpindi, D.I. Khan divisions and Nisarabad subdivision of Baluchistan. The cotton
seed requires higher temperature for germination and early growth, G Herbassium and
G Arborium are extremely tough varieties and can be grown even under most
unfavorable conditions.
At the beginning of 20th century only short staple cotton were grown in Punjab,
Sind and other provinces of India. With the introduction of irrigation system in this
Sub-continent and due to the expansion of textile industry in great Briton, the American
type of G. herbassium group i.e. superior quality cotton were introduced in Punjab and
other areas for cultivation. This cotton spread all over the sub-continent gradually but
could not be become successful in most areas of Rawalpindi division at higher altitude.
Experiments have shown that excellent growth and development of best quality fiber
can take place even at 7500ft above see level i.e. Murree hills but cotton boll rot is a
very common disease over there hence good quality fiber can not be obtained. In desert
areas with low or no rainfall at all but with available surface irrigation system good
crop can be obtained provided the crop is well saved from dust and sand storms
particularly at the early stages of growth. It has been analyzed that words finest cottons
are grown in the fertile area of maximum relative humidity like western and eastern cast
of U.S.A. Banks of a river Neal in Egypt and Sudan and even some in lower Sind and
near Arabian Sea can be grown if proper researches are done.

3) Time of Sowing;
At the end of 19th century when canal irrigation system was just introduced in
Punjab, the month of March was considered very suitable for cotton sowing due to
deeper water level and lack of vegetative growth in the Canal Zone. More over dust,
sand, storm were common from April to August and temperature range was very high
with the rise water table, due to excessive seepage through irrigation radial changes
now being observed and suitable time for sowing to obtain high yield of cotton in
different tracts of Pakistan is as under;
Sr.No Division District Variety Time of Sowing
A Punjab
1 Rawalpindi Attock,Rawalpindi,Jhlum Desi From last week of
March_mid april
2 Gujranwala Sialkot,Gujranwala, Gujrat Desi 2nd fortnight of april
American 1st fortnight of april
3 Lahore Lahore, shikhupura, Kasore Desi 2nd fortnight of april
American
4 Sargodha Sargodha, khushab, Bakher, American 1st fortnight of May
Mianwali Mid March to early
April
Desi Do
5 Faisalabad Faisalabad, Jhung, T.T.Sing American Whole month of May
6 Multan Sahiwal // Do
Multan, Khanawal, Vahari American Last week of May to
whole month of June
7 D.G. Khan Layya, D.G.Khan American Mid March to early
April
Rajunpur, Muzafergur // 3rd week of May to 3rd
week of June
8 Bahawalpur Bahawalpur American Mid May to 1st week
of June
R.Y.Khan,Bahawal Nagur // 3rd week of May to 3rd
week of June

B Sind
1 Hydrabad Thur Parker American 1st April last week of
April
Hydrabad // 10th April to 10th May
Sangar // Mid April to mid
May
2 Sukhar Sukhar, Nawab Shah // 1st May to 20th of May
Nawab Shah Desi //
C N.W.F.P
1 D.I.Khan D.I.Khan American 3rd week of April to
end of May

Sowing should preferably be done in the recommended period. All varieties to

give max yield, only, if they are soon in time. Early sowing unnecessary extend the
growth period where as late sowing result in low yield and poor fiber characters hence
it should be avoided at all cast.
The entire sowing cannot be controlled by the cotton grower and roughly from
30 to 40% of the cotton crop is always planted late due to unavoidable circumstances.
This situation however much better in areas where good subsoil water / (where ground
water is not saline or alkaline) with installation of tube well to supplement water
deficiency.
In experiment cotton sown during March in Thul zone yielding 500 – 600
kg/acre, in April, cotton yield was 300 – 400 kg/acre, in May planting yield further
reduce to an average of 150 – 250 kg/acre and finally for fine sowing it remain only 50
– 100 kg/acre under identical conditions of cultivations. In case of early sowing there is
too much vegetative growth (unnecessary development) which consume most of the
soil Nitrogen and water resources are consumed or exhausted by the time flowering and
fruiting starts, which caused bad opening of boll resulting in low yield of immature
seed and fiber.
On the other hand if time of sowing is late that is May or June or even more late
the growth of plant and its development will be limited, attack of cotton jasid and other
pest will be maximum and hence yield will remain vary low. A way for covering loses
of yield due to late sowing is to increase the plant population. If sowing is done vary
late the distance between rose may be reduced from 30 – 36 inch to 18 – 24 inch or
even less and distance between plants may be reduced from 15 – 18 inch to 6 – 9 inch.
In desert area of Thul and Sind and Barni area of RawalPindi division where
water is limiting factor and in desert area evaporation ratio is too high and water loses
are more. The best system to get a reasonably good yield from any variety of cotton it is
recommended that cotton should be sown in rows with 12 inch row distance and 3 inch
plant to plant distance to get a large population over 1 lack plat / acre. The entire plant
land will thus be fully covered and evaporation from the soil will be least.
Researches at RawalPindi prevails that yield of cotton with normal spacing of 30
inch row to row and 12inch plant to plant with in row in May to June sowing the yield
hardly exceed 20 – 120 kg/acre with the application of fertilizer of all variety yield was
further increase from 42 – 200 kg/acre. Finally, for March and early April sowing with
12inch row and 3inch plant to plant distance with an average plant population of 70000
plants. Both Desi and American variety produced 400 – 650 kg/acre which is normal
yield Sahiwal and Multan zone.
 Time of sowing has a permanent affect upon the germination of seed seedling
vigor, growth and development, fruiting and ultimately yield of cotton. It varies from
place to place and from variety to variety. Early sowing favors vegetative growth where
as late planting keep the plant starve and in both these cases yield is vary poor. Sowing
is there fore to be determined in every cotton area o the bases of regular experiments so
that any changes in soil conditions, climate, unpleasant agronomic factor, plant
protection measures which affect cotton yield may be connected to the sowing time.
Moreover quality of cotton is also affected by the time of sowing and weather
conditions along with the period of plant development particularly immediately after
sowing and at the time of opening and picking.

Land Management;
The type of land its preparations and management positively affect both yield
and quality of cotton. In order to get high yields land must be leveled so that the
distribution of water on the whole field is uniform and plant get water supply on equal
bases. If field is irregular some places will have more water where as plants at higher
level will receive hardly any water, for their normal growth. Plant allocated for cotton
growing must follow a suitable crop rotation to maintain a satisfactory level of
nutrients. This means that sequence of crops following each other should be such that
cotton plants must produced better yield. Experiments have shown that cotton if planted
on a fallow (no crop for a year or so) plough but left on sown for a year. The yield will
be the highest cotton sown after Berseem, Shaftel, Junter, Gowara, and other similar
crops produced comparatively high yield.In case of cotton following after wheat and oil
seed crop the yield is some what lower. If proper inputs like fertilizer, H 2O etc are not
provided at proper time in sufficient quantity. The ideal way of the improving land, and
through suitable addition of crops lies in planting the leguminous crops which fit
nitrogen in soil and thereby increase their fertility. Green manuring of crop is another
way of increasing soil fertility unfortunately the pressure of population in most of
developing countries like Pakistan is too high and the average of land is so small than
farmer has no choice except to grow crops of maximum cash return like sugar cane,
vegetable, fodder, rice and cotton and most of these crops are sown during Kharif
season therefore there is a serious competition b/w there crops and only Govt. policies
and planning can support cotton crop in a positive manner.
6) Quality of seed;
The seed to be sown should be free from any infestation by insect, pest and
diseases, its germiability should be above 70%. The certified seed germiability, quality
seed also assure establishment of optimum plant population which is pre request for
good yield. The seed should be delinted to avoid the risk of seed born diseases and boll
worm larvae, the undelinted seed should be dried under the sum, for two or three days
daily for few hours to get rid of the pink boll worm larval. The undelinted seed should
be rubbed lightly with cow dung ash before sowing. This practice ensures free flow of
seeds through (the funnel of the drill. Soaking of the seed has the additional advantage
of enhancing %age of germination). The systematic seed multiplication system is being
discussed here in detail.
a) Nucleus seed plots:
Plots of cotton breeders where 100% selfing of the cotton crop along with
rouging (elimination of the undesirable plant) if any under the direct supervision of the
breeder is performed.
b) Breeders seed multiplication blocks;
When seed from stage 1 is sown where partial selfing, through rouging and mass
selection is exercised.
c) Seed ----- from stock No.2 is sown at the seed farm of the dept. of Agriculture and
seed supply corporation where complete rouging under the supervision of cotton
breeder is exercised.
d) Registered grower class 1
Where seed from stage No. 3 is sown and crop is again thrayly rouged.
e) Registered grow class 2
 When seed from stage N-4 is planted over a very large once and here partial
checking by the cotton breeders is exercised where as complete checking also provision
has to be arranged by the staff appointed under the control out (cotton inspector)
6) The seed from stage No. 5 after proper and careful ginning under the control of staff
arranged through the cotton control ct and seed supply corporations will be planted
again thoroughly rouged thrays the entire area will be supervised by the cotton
inspector with the help of the cotton grower.
For all these stages separate ginning machines both from GOVT and private
sector have to be reserved to gin this cotton under the strict supervision right from the
supply of seed to the cotton grower. It has been found that seed germination is better if
the cotton field is well prepared, soil moisture is sufficient and sowing of cotton is done
preferably early in the morning lat in the evening so that there is less loss of moisture
from the soil. Soaking of seed in the water for 4 – 6 hours before actual planting and
treatment of seed with a fungicide or any chemical which resist or simply a ferric
dusting is done so that individual seed may be separated and sowing of the individual
seed in the seed bed may be proper. If any variation is made from these conditions and
precaution the germination of seed or will be low and chances of survival of the
germinated seedling will be less.

Variety of cotton

The yield and quality of cotton is mainly determined by the variety of cotton being
cultivable. There are no of species grown all over the world under variant soil and
climate ranging inform desert to snow covered areas in north hemisphere. The wild
species of cotton in total are 39 in numbers are grown under different condition in
different countries and are famous for very specific characteristics particularly they
offer resistant (drought) attack of pest, diseases and tolerant against salt and other
unfavorable conditions. They have little or very low commercial importance but are
very valuable sources of highly desirable characteristics which may be transferred to
cultivated cottons through suitable breeding method. High strength is known to be
present in gossipium thurberri of Arizona (USA). This character has been successfully
transferred to America cotton USA and increase in fiber strength from 30 – 50 % has
been achieved. Group of cottons known as G. Arborium and G. Herbacium posses’ high
rate of resistance against the attack of pests and diseases draught and etc and in general
such varieties produce comparatively greater yield and as compare to bar be dense
group of cotton.
Desi Cotton of Punjab;
(Indigenous or local variety) and Sind belong to G.Arborium cover the entire
area under cotton up to 1914 of course, there were plants of varieties belong to G.
Hersutum imported by East India company and brought by then local solders and
warmusia to certain foreign country under British rule, Department of agriculture was
established in Punjab and all other provinces of India 1915 and research work for the
improvement of cotton crop was then taken up. British GOVT wanted to expand its
textile industry in UK and they were in need of medium and longer staple cotton and
hence import of such cottons from USA stated. GOVT encouraged and supported the
extension and development of fine quality cotton industry in the Indus valley. The area
under cotton crop started increasing with the extension of canal irrigation system. The
great demand for better quality cotton from abroad resulted in the replacement of Desi
cotton by Punjab American cottons of G. Hersutum group. As already indicated Desi
varieties covered almost 100% cotton area up to 1914 which now reduced roughly from
10 – 12 % at the time of independence and more or less the same situation prevails at
present.
1) 4F / 1914:
 4F was first variety of medium staple cotton evolve at Lyalllpur and increased its
cultivated area in the Punjab and Sind and even in other parts of India.
2) 289F / 1921:
The 2nd variety of cotton which was some what longer in staple was 289 F and it
replaced 4F in Multan, Behalpur divisions and parts of Sind.
3) 289F / K-25 & LSS / 1933:
Both these varieties were evolved in 1933.
4) 289F / 43 /1934:
Among these three varieties LSS became the major commercial variety of cotton
in Punjab particular in the central canal zone i.e. division of Sargodha, Lahore,
Rawalpend of India.

(14/16, 15/16, for L-SS)

4F and LSS together were able to spin 16 and 30 single count yarn respectively and was
used for the medium type of cloth and these variety became famous all over the world
on account of their staple length, special color and strength. Researchers were
intensified in Punjab and Sind particularly in 1935 and no of research stations were
established at Jhung, Multan, Khaniwal, Hansi (east Punjab in India)
124F:
124F new longer staple cotton was evolved ad approved, in 1944 and it replaced.
289F, 4f, AND 289f / K-25 over a very large area in division of Multan and Bahawalpur
and continue is hold in hold in Multan region right up to 1961, when AC 134 totally
replaced all other verities in Punjab.
238F was evolved at Sahiwal during 148 268F at Jhang in 1948, 216F at
Lyallpur in 1946. 216F became the major common variety of cotton in East Punjab and
South India.
AC – 134 and Lasani – 11 /1959:
AC – 134 were evolved and approve in 1959 and immediately started replacing
other varieties in different cotton growing area. Out of desi group, 12 – S, 119 – S and
39-M, M6A2 became leading commercial variety in Punjab and India during 1932 till
1959.
Pakistani cotton as a group created a name in the world market for their special
strength in respective length group and was preferred over all other cotton for the
manufacture of certain end product. 4F, LSS, 289-F, AC-134, L-11 and M-4 (Anto of
Sind) were famous all over the world in their respective jine. AC-134 was the major
commercial variety of cotton in Punjab and as a matter of fact for many years and ruled
a very large cotton growing area in Pakistan.
B – 557:
It was released in 1975; it is another leading variety of cotton which replaces
AC-134 in Punjab. Komila cotton of East Pakistan was most famous cotton for its
shortest, coarse staple and in great demand in the world market particularly in USA for
use in the manufacture of carpet, mats uprdkfkdf and for wool blending.
A no of varieties like 268F SL, MS-39, MS-40, 149-F and Deltapine (DPN), but
also reach commercial stage but failed due to their certain undesirable plant
characteristics e.g.268-F of Jhang was very poor germinator MS-39, MS-40,149-F and
DP failed due to their great susptability due to the attack of various pests particularly in
the year of high rainfall.
In Sind area 4F, 289-F and other Punjab cotton have been grown by the Punjab
settler over their (in addition to M-4 (NT Sind) was the major staple variety of cotton).
------- A no. of new variety like M-4, M-100 – Sarmas and qualldri have been evolved
which to be superior in quality.

7) Plant population;
The yield of cotton is directly dependent upon the no. of plants per acre of
course subjected to the fertility of the soil as lesser no. of plants on a very fertile land
can produce as high a yield as the large no. of plants as a comparatively poor soil under
natural condition plant population in case Desi cotton of G. Arborium group should be
about 25000 plants per acre and that of medium and long staple of Punjab American
cotton commonly called Narma should be about 20000 as a heavy and very fertile soil
even a plant population of 10 15000 plant / acre will produce a very yield. However on
comparatively poor soil of low fertility or on new lands where cotton is going to be
planted for the 1st time or in desert and barani areas a very large plant population is
required to get reasonably high yield of cotton. In case of very late sowing due to
unavoidable circumstances large no. of plants per acre are also essential plat population
can be raised through the following system.
a) Seed rate of 8 -10 kg/acre in case of American types and 5 – 6kg/acre in case of Desi
cotton will provide the required plant population
b) Sowing of cotton in rows of 75 cm apart and 30cm in row of plant to plat will
provide a population of 25000 after necessary thinning or removal of weak plant.
c) Sowing of cotton in rows 60 cm apart and even 45 and in extreme cases 37cm
distance according to the condition will provide high plant population.
In general plant population in Pakistan varies from 7 – 10 thousands per acre
against the recommended practice of 20000 plant and therefore this is the major factor
for low yield in Pakistan compared to the other countries where plant population is
normally b/w 20 – 40 thousands plant. Thus with such a low plant population the
supplementation of irrigation water fertilizer, chemicals and pest control measures
remains ineffective.
8) Crop rotation and soil fertility;
Not a single crop can be grown year after year on the same field as soil fertility
goes on decreasing. Hence a certain rotation or sequence of crop one following the
other has to be arranged to maintain or improve soil fertility. Due to the high pressure of
population and small holding per family cotton is normally grown after wheat on 60 -70
% of the cultivated area and the other corps on rest of the 30 % proper balance B/w
nitrogen
Potash and Phosphors is necessary for obtaining high yield and for this purpose balance
fertilizer in advance cotton growing country. In Punjab it has also become a practice to
sow wheat first after the lost picking of early maturing varieties of cotton with the help
of fertilizers greater investment in machinery tractor, implements and tube well. This
practice is becoming very popular as it increases the intensity of cropping by providing
22 – 25 lack acre or even more for additional planting, thereby partially solving the
good problem as well.

9) Irrigation;
Cotton is sensitive to excessive moisture as well as stress conditions. Both result
in shedding of squares, flowers, small boll and leaves in cotton. Irrigation applied in
time at proper interval and in correct quantity helps to plant to maintain its normal
growth and bear fruit. (In case of ridge sowing seeds should be dibbled just above the
water mark. Subsequent irrigation may be given more frequently). Irrigation
requirements of cotton crop in the country vary from one ecological zone to another.
The following irrigation schedule is based on research finding, (may help the
formers)

a) For Punjab:
In order to get good plant stand if cotton follow wheat, double “rauni” may be
applied to make the soil profile wet up to the specific depth.
In case of water scarcity one single rauni (soaking dose) of 12.5 cm can be done.
The 1st posts showing the irrigation may be administered at 15 day intervals in
accordance with the soil condition and plant requirement. Incase of varieties like NIAB
– 78, the first irrigation should be given after 30 days of sowing, because these varieties
are short stature and enter into effective fruiting phase earlier than others. The
subsequent irrigation interval in case CIM – 70 should be decrease to 12 – 15 days. The
Punjab varieties require from 5 – 6 irrigation in total of 30 inch of water during the
length of growing period partially through irrigation and rain. The frequent rainfall will
definitely decrease the number of irrigation.
 The last irrigation may be completed by the last week of September or in the 1 st
week of October depending on the variety and soil type. However if temperature
persists in the month of October and in case of late maturity as happened during 1987 –
88 irrigation may be continued up to the month of October.
b) Sind:
One soaking dose of 8 – 10cm is enough to wet the soil profile up to the desired
depth. The 1st posts sowing irrigation may be given after 32 – 35 days of sowing and the
subsequent irrigation may be given at 15days interval keeping in view the soil and
weather condition. If plants show wilting (dropping of leaves) at mid day, the field must
be irrigated with out to avoid the excessive fruit shedding. The irrigation may be
terminated in Hyderabad, Therparker and Sangar districts in the 1 st week of September.
In case of late sown crop, it may be stopped in the last week of September. In Nawab
shah, Dadu, Kairpur and Sakher districts for normal sown crop.
It should be stopped in the last week of September. In case of late sowing of
cotton the irrigation may be required up to the early October.
In the water logged area 3 – 4 irrigation will be sufficient however yield of
cotton also depends upon the quantity of water applied. In the irrigated state of
California, USA one cusec of water is available for 60 – 70 acre of land where as in
Pakistan and particularly in Punjab one cusec water is proved for 350 acres i.e. cotton in
California gets more than 5 times water for maturity that Pakistan i.e. again the reason
why cotton crop sown in gardens gives 1000 – 1400 kg/acre. Hence H 2O is one of the
major limiting factors for the increase of cotton production in one country.

10) Plant Pests;

About 30-40% of cotton crop is lost due to attack of various pests and diseases.
Pest attack is always behind if sowing is done late plan population is less, (variety is
never hairi type) and in the reasons of high humidity and rainfall. Cotton plant is
damaged and serious losses in yield have been reported in the past due to the attack of
following pests.
a) Cotton white fly.
b) Cotton jassed.
c) Boll worms, spotted or pink.
d) Cotton leaf rollers.
e) Cotton boll weevil.
f) Army worm.
Cotton white fly attack is serious in dry season and drought condition, where as
cotton jassid is found in large number and damages is more in wet and humid season.
Cotton leaf roller attack is serious in Phalia, Bhalwal, Jaranwala, Khanwal and
is widening to the adjacent areas. It is found in areas closer to the forest plantation.
Cotton Boll Weaval has been such a serious pest in USA that it is imoron to
every one and is responsible fot the total failure of sea Island cottons, Late maturing
long and extra long cotton of Hersutum group also.
Army worms have been imported from USA, the introduction of delta pine
smoothly variety of cotton and has been spreading widely due to tobacco crop and even
vegetable are being damaged seriously by this pests. A fall development of the cotton
crop can only be attained if adequate control of damage by insects pests and diseases is
effective. The cotton plant is usually attracted to insects and probably no other
cultivated crop has as large list of insect, emimees among these some are the most
destructive pest in the history of agriculture.
The best way to fight the pest attack is to breed varities of cotton resistant to the
attack of different pests and diseases and this is the simplist cheapest and most effective
method. Certain agronomic practices like clean cultivation of land, burning of waste in
farm collection of stubbles from the cotton field and burning them adjustment of the
planting time and plant population have been found to be very effective. Early maturing
varities of cotton can help in werting against the attack of certain pest like boll worms.
 Chemical dusting and spraying and biological control of pest can also be put to
advantage. If done properly at proper time and right types of dozes are used. In Pakistan
however after a long time a complete chemical control of pest is now achieved due to
the privatization of pested business.
Tow groups of organic chemical are commonly used;
1- Chlorinated hydrocarbons.
2- Organic compounds.
1 include DDT benzene hexa chloride aldring endron toxaphene different
chlorinated hydrocarbon compound kill different insect e.g. DDT will not control boll
weavel but other compounds listed above can be used for this purpose.
Group 2 include methyle parathione and ghusathion. More recently various
combinations od the tow types of insecticides have been used (introduced) and present
data treatment now provide effective control of the main cotton pest even though there
has been a serous question commonly raised about the health hazards of these
pesticides.
11) Plant Diseases;
In general cotton diseases are not as serious a problem as that of insect pest has
been but there are areas and seasons in which cotton diseases causes excessive losses
particularly due to unfavorable climatic condition such as excessive cold and humid
weather. Common diseases are the following;
a) Tirak or back opening of bolls.
b) Root rot of cotton.
c) Angular leaf spot (bacterial blight)
d) Boll rot
e) C.L.C.V
1) Tirak is the physiological disorder of plant caused due to nitrogen and H 2O
deficiency at the flowering and fruiting stage. From the end of August to the end of
fruiting season on saline or alkaline soil and even on normal soil particularly at the time
of flowering these conditions may be become further serious due to high velocity winds
even for shorter duration. The nitrogen deficiency causes are diagnosed through
yellowing and reddening and final shedding of leaves as water deficiency is indicated
by the entropian of leaves of the plant in the after noon. Triak results in the bad opening
of the ball immature seed and fibers with low yield of poor quality. Bad opening or
premature opening and of bolls has been the cause of serious decline in cotton yield. (A
no of times since 1914) and in this respect cotton variety of G. Hersutim group suffer
much more than short staple Desi cottons. Tirak can be avoided through the additional
supply of nitrogen and irrigation H 2O at the time of flowering and fruiting through
fertilizers tube well etc.
2) Provisions of protective hedges and croops to minimize evaporation and transpiration
due to high velocity wind.
Root rot of cotton is found all over the world mostly in Peru and USA and it is
more common in Sind than the Punjab where it is found in patches. A perfect healthy
crops starts dropping leaves.
The following interim measure are suggested to minimize this disease incidence.
Sowing cotton after leguminous crops like luserne and berseem which needs large no of
irrigation and make the soil loose permitting penetration of H2O along this the
application of potash fertilizers also help to improve soil texture. Later researches in
Punjab have shown that there are certain types of Fungi which is introduced in a root
rot effected soil grows so faster that they stop the multiplication of harm full Fungi.
Bacterial Blight: This disease appear on the leave in the initial stage but if the
humid conditions prolong due to cloudy weather and frequent rains the disease may
shift to the bolls resulting in their shedding. It is more common in Punjab. Its chemical
check has not been found very effective. The only remedy is the development of
bacterial blight resistant varieties however following steps may be taken to check this
disease.
1) Use of acid delinted cotton seed.
2) Soaking of seed in 0.2% solution of vitavax or any other effective systemic
bactericate before sowing.
3) Burying of infested plant dabries by furrow turning plough or cultivating the field
and if possible irrigating them immediately to faster rottening of the trash.
4) Boll Rot is strongly correlated with the intensity of light penetration down to the
bottom bolls. Humid conditions accelerate near the soil surface aggregation the fungus
growth on the bolls. Excessive vegetative growth should be checked by adjusting
irrigation and nitrogenous fertilizer according to the requirement of the soil.
12) Plant protection measures;
There can be no two opinions about the roll of the plant production in optimizing
cotton production. The significance increase in area treated with insecticide during the
fast few years is a testimony of it. Followings are the details of few measures.
1) Cultivation of varieties, resistant to the attack of pest and diseases. Desi cotton and
wild cottons are definitely more resistant to the attack of all types of pest and diseased,
although resistant type can be developed and evolved in Hersutum group of varieties,
by simple selection or hybridization followed by selection. However transfer of
desirable genes from wild cottons to Hersutum groups seems to be more useful and
effective.
2) Agronomic control of pest and diseases by clean cultivation adjustment of sowing
date plant population along with evolution of early medium and late maturing varieties
under different conditions can be definitely held to improve the exiting condition.
3) Chemical control of pest and diseases.
By dusting and spraying some progress has been made in this direction in
Pakistan during the last 30 years.
Chemical control of pest and diseases is now becoming successful because, now
public and private sector is working in collaboration with GOVT agencies.
4) Biological control of pest and diseases.
The chemical control results in (in discriminate ) destruction of useful
insects (parasites and predators) along with the destruction ones and therefore
biological control i.e. increasing the population of predators and parasites according to
the environment in specific locality will be more useful. This technique is still in earlier
stage of development and will take fairly long time to be operational.
13) Cotton control Act;
Before partition the world demands for Pakistani cotton was mainly due to its
superior order in quality uniformity and cheap market prices along with other factors.
The chances of mixing takes place au at the following stages.
1) Natural Crossing; between different varieties or b/w good and bad quality plant in
the same variety cotton unlike wheat and certain other crops is net 100% self pollinated
and various degrees of cross pollination occurs in the field. The cross pollinated agents
au different types of insects which move from place to place and field to field and
usually. Visit cotton flowers for the collection of nector or honey and directly early the
pollens. The pollen thus travels or shifted from one flower to another and from one
variety to another variety which may be the source of deterioration in different quality
characters.
Hence it is recommended like USA where variety cottons communities are
advocated which apart from many other advantages help in practically illumination
cross pollination in the field as well as seed mixing in ginneries.
2) Poor quality of seed used for sowing.
3) Frequent possibilities of admixturing at the ginning factories.
4) Careless picking and storage by the cotton growers.
5) Middle man. Factory purchases through middle man. At the far off places of trade
and commerce the factory owner purchases the cotton through their local agents and
they apply a no of adulteration practices.
Punjab cotton control act 1949 was enforced to maintain the purities of cotton
varieties, because immediately after independence due to the migration of the
population the experience cotton grower to the Pak Punjab shifted to India and in
exchange former from barani area came to settle here. The new settler has no specific
experience of irrigated land s particularly in cotton crop cultivation started their old
technique of mix crop growing. Hence cotton crop of Pakistan received a serious set
back in the international market to improve and rebuilt the reputation of Pakistani
cotton in the world market. The provincial GOVT has to enforce Punjab cotton act.
Then, came the Behalwalpur cotton control act in 1950 which was further extended in
Hyderabad and Khairpur division and finally Pak cotton control act came in 1967.
Provision of the cotton control act:
1) Constitution of cotton control board and advisory committee for the enforcement of
the act.
2) Appointment of Inspectors and Chief Inspectors for the enforcement of the act.
3) Administrative control of ginning pressing, and cotton seed oil factories by
a) Issue of licenses for working.
b) Issue of licenses for extension or modification of factory.
c) Change in occupancy or ownership.
d) Proper record keeping by ginning factories for their seed cotton purchases, cotton
bales ginned and pressed , and sale of cotton seed and lint.
5) Filing of weekly and monthly return and of ginning and pressing by ginners with the
Agro Dept.
6) Marketing of cotton bales in a specific manner indicating code no of ginning factory
no. of lot serial no. of bales variety of cotton year of growth etc.
7) Use of correct scales and weighment by ginners.
8) Prohibition for inter varietals admixture, excess watering, adding seed or mixing
cotton waste, and other foreign matter.
9) Growing of particular variety only in particular zone for maintaining purity of that
variety.
10) Restriction on transportation of seed cotton and lent from one zone to another
without specific permission.
11) Arrangement for procurement of pure variety seed.
12) The act empowers the GOVT for fixing the maximum and minimum prices for seed
cotton and lint cotton.
13) The act has provision for introducing cotton grading.
14) Cotton ginning;
Cotton as it is picked from the field still contain seed and is known as “Kapas”
or seed cotton. Fibers constitute about 1/3rd of the total weight of the seed cotton and
rest being seed the proportion of lint to the seed cotton varies considerably with
different variety and is usually small for fine cotton. The ginning process may either be
roller ginning or saw ginning. In as a roller gin the main components are
a) A fixed knife
b) A moving knife
c) Leather Roller.
The seed cotton is fed into the gin stand manually the moving knife with a
vertical action against the fixed knife shapes/squeeze the cotton fiber from the seed the
cotton is then engaged by the revolving leather rollers, which carries it and drop it in
front of the gin. One single roller gin has a capacity to produce about 35 lbs of lint per
inch per hour while a double roller may produce so lbs per inch per hour.
The saw ginning process consists of s series of circular saws mounted on a
horizontal shaft. These saws project through a set of steal ribs and as the cotton is fed
on the ribs a tearing action is developed between the Kapas and the saws and carried
through the ribs. The fiber is then removed from the saws by brushes or by air suction
and conveyed through a condenser to a bailing press.
Pressing and bailing;
After having it separated from seed of the fiber it carried to the pressing, until
pressing the lint into a bales size is made for its handling and marketing.( because of its
voluminous nature. There are three types of cotton baling pressing depending upon the
degree of density. Into which they press the bales). The function of baling press is to
compress the cotton into a particular dimension. In Pakistan there are standard density
presses which usually press about s380 lbs of cotton into a size of 12.25 cubic feet or a
density of 32 lbs per cubic ft.
Installed capacities
 There are as many as 1035 ginning factories in Pak (Punjab ¾) Sind ¼ th of the
total with a ginning capacity of 20 million bales.
Mechanical Harvesting:
Ginning is the act of separating lint from seed by mechanical means to give spin
able cotton and undamaged seed. The lint is not attached so firmly to the seed that it
cannot be pulled off readily by hand, but a day; work may give less than a kg of lint. An
early from of hand gin used in India was the ‘Churkha” in which the lint was drawn
between a pair of wooden rollers. Leaving behind the seed which could be not pass
between them, but the process was still slow and it was not until the invention of the
saw gin by Eli Whitney in 17 93 in USA, that the burrier to expansion of the textile
industry was broken.
1) Roller Gin:
In a roller gin the main components are
i) A fixed knife (or blade)
ii) A moving knife
iii) Leather roller
there are many variations and refinements roller gin, but basically it consists of a
leather covered roller which is made to revolve in close contact with a fixed metal
blade, the lint in the red cotton sticks to the leather roller and is pulled through the gap
between the roller and blade, which is two narrow for the seed to pass. The separation is
helped by a moving knife with a vertical action against the fixed knife shaves the cotton
fibers from the seed. The lint is lifted off the roller while seed follows its own channel.
One single roller gin has a capacity to produce more than 25 kg/hr while a double roller
gin may produce more than 80 kg/hr.
Saw Gin:
The saw gin consists of a series of small circular saws. Between 12 – 18inch
(300 and 450 mm) in diameter mounted closely on an axle (horizontal shaft) and made
to revolve at high speed in order to tear the lint away from the seed cotton. The saws
project slightly between bars or a set of steel ribs so spaced as to prevent the seed from
going forward with the lint.
The seed cotton is fed continuously into a rounded box or through, and the action
of saws keeps it revolving in a loosely compacted roll. The seed falls through a grid into
a collecting box or seed conveyer, while the lint is whipped off the teeth of the saws by
high speed brushes or air blast.
Each manufacture has own modification of the basic design. The small early gins
were fed by hands, but modern gin, have automatic feed system. The average saw gin
turns out 500 kg of lint in an hour.
Roller Compared with Saw gin:
Broadly speaking, roller gin, are used for ginning the long staple cottons of the
world e.g. G. barbadense crops of Egypt and the Sudan, the Sea Island cotton of west
Indies and the Pima cotton of New Mexico and Arizona. The action of the roller gin is
gentler and damaging to high quality lint which, may be broken on “gin-cut” in a saw
gin, shortening the mean staple length. Some scientists considered that any cotton with
a staple longer than 35 mm ( 13 / 8") should be roller ginned.
For the same size of machine, the output of the roller gin is much less than that
of saw gin. A 40" roller gin is roughly the same size as a 40 – saw gin, the former
turning out about 50 kg of lint per hr. and late about 500 kg. The saw gin requires a
more powerful motor, but is more efficient in that it uses considerably less power per kg
of lint. The roller gin produces between 1 and 2 % more lint than a saw gin from a
given quantity of seed cotton. The lint from a roller gin is smoother in appearance and
has a luster which is absent from the fluffy lint from a saw gin. Probably because the
gently action of R.G removes less dust and trash.